导航组件currentDestination在按下后退按钮之后为null

我已经使用导航组件（v2.3.2）实现了导航流程。当我第一次测试流程时，一切正常。但是，当我按“后退”按钮返回到主页片段并再次尝试测试流时，由于currentDestination为null，应用程序崩溃了。当我按下后退按钮时，导航组件似乎卡住了。

错误：

java.lang.IllegalArgumentException：导航操作/目标com.tridie2000.myapp：id / action_fragmentA_to_fragmentB不能从当前目的地Destination（com.tridie2000.myapp：id / fragmentB）label = b_fragment class = com.tridie2000.myapp.presentation .fragments.BFragment

这是我在MainActivity中配置导航组件的方式：

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        setupBottomNavBar()
        setupNavigationUI()
    }

    override fun onCreateOptionsMenu(menu: Menu): Boolean {
        val inflater: MenuInflater = menuInflater
        inflater.inflate(R.menu.main_menu, menu)
        return true
    }

    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        val navController = findNavController(R.id.nav_host_fragment)
        return item.onNavDestinationSelected(navController) || super.onOptionsItemSelected(item)
    }

    private fun setupBottomNavBar() {
        val navController = findNavController(R.id.nav_host_fragment)
        val bottomNav = findViewById<BottomNavigationView>(R.id.bottom_navigation)
        bottomNav.setupWithNavController(navController)
    }

    override fun onSupportNavigateUp(): Boolean {
        val navController = findNavController(R.id.nav_host_fragment)
        return navController.navigateUp()
    }

    private fun setupNavigationUI() {
        val navController = findNavController(R.id.nav_host_fragment)
        setupActionBarWithNavController(navController)
    }
}

这是MainActivity的布局代码：

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".presentation.activities.MainActivity">

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottom_navigation"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@color/themeColor"
        app:itemIconTint="@drawable/my_nav_bar_item_color"
        app:itemTextColor="@drawable/my_nav_bar_item_color"
        app:labelVisibilityMode="labeled"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:menu="@menu/main_tabbar_menu" />

    <fragment
        android:id="@+id/nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:defaultNavHost="true"
        app:layout_constraintBottom_toTopOf="@+id/bottom_navigation"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:navGraph="@navigation/nav_graph"
        tools:ignore="FragmentTagUsage" />

</androidx.constraintlayout.widget.ConstraintLayout>